Feeder chewing up filament

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I have an Ultimaker 2 go and have noticed that on long print it chews up filament constantly. I have to sit and watch it print and when i notice under extrusion I remove the filament, cut off the flattened part, reload it and the print continues very well. I have tried messing with the adjustment on the feeder tension but it hasn't really made a difference. I am printing ultimaker pla at 210 degrees at 50mm/s.

Any help would be much appreciated,

Thanks,

Speedy

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Someone else had an issue with the feeder gear becoming too hot and flattening out their PLA as it rolled between the knurled wheel and the bearing. That was solved by cooling the feeder, and I think it was in this thread.

Just in case though, you can check to make sure your filament isn't getting caught on anything as it's feeding in, and that there's no excess material in the feeder or nozzle.

Edited July 14, 2015 by Guest

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Interesting the recent threads mentioning the possibility of the feeder stepper motor heat causing filament softening issues - there's loads of threads on here about extruding issues/underextrusion, etc, but its only recently i've noticed anyone suggesting the feeder motor as a possible contributing factor or has this been discussed before?

Does seem feasible with hot external temp some people are experiencing i suppose - and the suggestion of a cooling fan on the stepper motors makes sense.

In fact all the motors do get very hot in normal use - is there any benefit to cool all 3 motors i wonder?

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The heating issue sounds likely so I may buy a desk fan and sit it next to the feeder to solve that problem.

Is there anything I should check for with regards to the motor connected to the grinder wheel? I've noticed that on retraction the motor clicks but not on extrusion. Any ideas as to what that could be?

Thanks for the help so far.

Speedy

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Is there anything I should check for with regards to the motor connected to the grinder wheel? I've noticed that on retraction the motor clicks but not on extrusion. Any ideas as to what that could be?

When the feeder kicks back (says "tock"), it indicates that the filament is unable to forward for some reason. This can be due to either a clog in the nozzle, some pressure/excess material in the Bowden tube or feeder, or just trying to print too fast. If it's happening on retractions, it could be caused by the change in pressure in the Bowden tube when the retraction is over and the filament is pushed back up to the nozzle.

What are the retraction settings you're using? And have you changed filament other than unloading to cut the ends off, or done the Atomic method yet? Are you using the filament guide that came with the printer? I can't remember if they stopped shipping those with the UM2Go or not, but if you are it's not necessary and could be generating undue friction on the filament as it feeds. This could contribute to the grinding issue as well.

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Is there anything I should check for with regards to the motor connected to the grinder wheel? I've noticed that on retraction the motor clicks but not on extrusion. Any ideas as to what that could be?

When the feeder kicks back (says "tock"), it indicates that the filament is unable to forward for some reason. This can be due to either a clog in the nozzle, some pressure/excess material in the Bowden tube or feeder, or just trying to print too fast. If it's happening on retractions, it could be caused by the change in pressure in the Bowden tube when the retraction is over and the filament is pushed back up to the nozzle.

What are the retraction settings you're using? And have you changed filament other than unloading to cut the ends off, or done the Atomic method yet? Are you using the filament guide that came with the printer? I can't remember if they stopped shipping those with the UM2Go or not, but if you are it's not necessary and could be generating undue friction on the filament as it feeds. This could contribute to the grinding issue as well.

Thanks for the reply Remy,

My retraction settings are the stock ones (min travel 1.5mm). The UM2Go did not ship with the filament guide so there cant be any problems from there. I have done the Atomic Method many times and it has not changed the click in the feeder on retraction.

The click only occurs when filament is moving backwards and not forwards which is the baffling thing here.

Any further help would be much appreciated,

Thanks,

Speedy

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The click only occurs when filament is moving backwards and not forwards which is the baffling thing here.

Um - a video would help. Are you sure the click isn't *causing* the retraction? Are you sure it's an intentional retraction? Because what you describe sounds like the kind of click that you hear when you lose some steps. It happens all the time when there is too much pressure.

210C, 50mm/sec is fine as long as you are doing .1mm layers. At .2mm layers that's too much and so you need to increase the temp (pla is more like honey at 230C and more like toothpaste at 190C).

here are my recommended top speeds for .2mm layers (twice as fast for .1mm layers):

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

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In fact all the motors do get very hot in normal use - is there any benefit to cool all 3 motors i wonder?

This problem came up last summer as well. And also with someone in Brazil during their summer.

The heat isn't bad for the stepper motors - but it makes PLA soft if the PLA gets above 52C.

If you are printing ABS and want to raise the air temp to 50C inside the printer the steppers should be okay but any hotter and you should probably put fans on all three steppers on the inside of the machine (Z stepper should be fine).

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The click only occurs when filament is moving backwards and not forwards which is the baffling thing here.

Um - a video would help. Are you sure the click isn't *causing* the retraction? Are you sure it's an intentional retraction? Because what you describe sounds like the kind of click that you hear when you lose some steps. It happens all the time when there is too much pressure.

210C, 50mm/sec is fine as long as you are doing .1mm layers. At .2mm layers that's too much and so you need to increase the temp (pla is more like honey at 230C and more like toothpaste at 190C).

here are my recommended top speeds for .2mm layers (twice as fast for .1mm layers):

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

Thanks gr5,

Will try to get a video of the retraction when I am printing something that utilises it, currently printing a one piece spring so the feature is not being used.

The retraction of filament is definitely on purpose as it is when the print head jumps from 1 side of a print to another. The filament retracts fine as well, there is just a subtle click as this happens.

Thanks for your help so far, it is much appreciated .

Speedy

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The retraction of filament is definitely on purpose as it is when the print head jumps from 1 side of a print to another. The filament retracts fine as well, there is just a subtle click as this happens.

The retraction itself makes a sound (says "beep"). There's a video of it below.

If this is what is happening, this is normal. However, if your feeder is making the "tock" sound instead, that would be the kick back caused by pressure or blockage. There's a video of the "tock" sound below.

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It is a faint tick or click. The increased temperature from 210-230 seems to have helped with the chewing of filament however.

The increased printing temp is moving filament more quickly through the nozzle, so less time for the gear to grind away at it. Also a rule of thumb is the faster you print, the hotter your nozzle temp needs to be and vice versa (cooler temps, slower print speeds). Good to hear you resolved the grinding at least.

However I'd be very interested to see a video of this faint clicking noise. Is there anything moving about on the print head when the filament retracts? Sometimes the white collet that the Bowden tube slides into can jump with the tube when the filament is retracting if the blue horseshoe clip doesn't have a good grip on it, or if the collet has worn away.

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It is a faint tick or click. The increased temperature from 210-230 seems to have helped with the chewing of filament however.

The increased printing temp is moving filament more quickly through the nozzle, so less time for the gear to grind away at it. Also a rule of thumb is the faster you print, the hotter your nozzle temp needs to be and vice versa (cooler temps, slower print speeds). Good to hear you resolved the grinding at least.

However I'd be very interested to see a video of this faint clicking noise. :OIs there anything moving about on the print head when the filament retracts? Sometimes the white collet that the Bowden tube slides into can jump with the tube when the filament is retracting if the blue horseshoe clip doesn't have a good grip on it, or if the collet has worn away.

Sorry for the late reply :(, I was away on holiday.

This video shows the clicking noise. It is best heard nearer the end of the video and occurs with the beeping sound on retraction.

If you have any idea what it could be caused by please let me know and thank you again for your previous help.

Thanks for the video. It sounds like when the filament retracts, something is rubbing on something else. I actually saw the material on the spool moving back during a retraction, could it be the spool catching on something?

Else, it may be something inside the feeder. A lodged piece of filament stuck on the extruder gear? The beep-beep of the retraction sounds normal enough, but the scratchy sound would indicate that there is definitely something rubbing somewhere when that happens. Does the noise occur at any other time or strictly only during retraction?

Thanks for the video. It sounds like when the filament retracts, something is rubbing on something else. I actually saw the material on the spool moving back during a retraction, could it be the spool catching on something?

Else, it may be something inside the feeder. A lodged piece of filament stuck on the extruder gear? The beep-beep of the retraction sounds normal enough, but the scratchy sound would indicate that there is definitely something rubbing somewhere when that happens. Does the noise occur at any other time or strictly only during retraction?

The noise occurs strictly at retraction. I will eventually find out why the noise is occurring but I currently have a bigger problem where the print head does not know where the centre of the build plate is so prints everything too far to the left.

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I've had a ton of issues with the material getting chewed up and I finally resolved it. The standard spring in the feeder is WAY to strong. The compression on the spring starts at "HARD" and goes to "CRUSH ME". I put in a slightly longer spring, about an 1/8 inch, and a smaller wire diameter on the spring. The result has been perfect for me. I can run TPE thru ABS and everything in between and no more grinding of the material. PLA used to be the worst. I literally had dust all in the tube and on the table on the back of the machine. So head out to the hardware store and buy a value pack of springs . Look for one with a smaller wire diameter and a little more length. I'd give you exact dimensions but my printer runs 24/7 and I haven't had time to take it apart.

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